Connector bar



W. R. SCHERER CONNECTOR BAR April 3, 1951 2 Sheets-Sheet 1 Filed Oct. 1,1948 ows/vrm Wayne R. Scherer ITIU/PIYF VS April 1.951 w. R. SCHERER2,547,413

CONNECTOR BAR Filed Oct. 1, 1948 2 Sheets-Sheet 2 58 INVENTOR.

f ay/v5 R. SCHERER ATTORNEYS Patented Apr. 3, 1951 Uil STATES PTENTOFFICE Application October 1, 1948, Serial N0. 52,245

2 Claims.

This invention relates to an improvement in connector bars.

Connector bars are provided in circuit breakers, which find varioususes, as, for example, in switch mechanism; and, mounted for rotation,carry contacts for the making and breaking of circuits.

As is well known, connector bars have heretofore been formed from metal,as steel, and of substantial size, since they are subjected toconsiderable torque due to the rapid opening when the circuit is broken.The metal bar is covered with an insulating material, as fabric orpaper, impregnated with a synthetic resinous material, as a phenolformaldehyde resin, which is molded to the contour of the bar, which isusually four sided. The contacts are clamped to the bar outside of theinsulating covering, which extends somewhat beyond the end of the metalbar to enable the ends to be sealed with insulating material.

Connector bars as heretofore made have been open to various objection inthat no means are provided to insure against endwise movement of themetal bar in the insulating covering, beyond the frictional engagementof the covering with the bar; and their production has only beenaccomplished by separately wrapping the bars.

Now in accordance with this invention from the product standpoint, aconnector bar, of the type indicated, is provided of such constructionthat the metal bar is positively held against endwise movement;v whilefrom the method standpoint procedure is provided whereby a plurality ofthe bars of the novel construction may be wrapped simultaneously withaccuracy and dispatch.

Having now indicated, in a general way, the nature and purpose of thisin'ention, I will proceed to a detailed description of a preferredembodiment of the product and of preferred procedure for the productionthereof, all with reference to the accompanying drawing in which:

Figure l is a side view of a plurality of connector bars assembled forwrapping with insulating material.

Figure 2 is a side view, partly in section, of a bar on completion ofthe wrapping,

Figure 3 is an end view of the subject of Figure 2.

Figure 4 is a side view, partly in section, after molding of theinsulating wrapping to the bar.

Figure 5 is an end view of the subject of Figure 1.

Figure 6 is a side view, partly in section, of com leted connector bar.

Figure 7 is a sectional view on line 'l-'l, Figure 6.

Figure 8' is a sectional view on the line 88 of- Figure 10, showing aconnector bar in a circuit breaker with the switch in an open position.

Figure 9 is a similar view showing the switch closed.

Figure 10 is a View looking in the direction indicated by the arrow inFigure 8.

The connector bar according to this invention, shown in Figures 6 and'7, comprises a metal bar A, of steel or any desired suitable metal, andsquare in cross-section, though the bar may have any suitable crosssection, as, for example, circular, triangular, hexagonal, octagonal, orthe like.

The bar A will be of suitable length for mounting in a circuit breakerand to carry the desired contacts and rocker arms between its ends.

Molded to the bar A, or otherwise closely conformed to the facesthereof, is an insulating material B, which may be a paper or fabricimpregnated with a synthetic resin having insulating capacity, as, forexample, a phenol formaldehyde type resin; and which may be applied bywrapping.

The insulating material, which is continuous, extends substantiallybeyond the ends of the bar A and is formed with a circular bore e sothat it extends inwardly at the end of the bar engaging its end facesand forming the bore 6, thereby providing abutments for the ends andpositively preventing endwise movement of the bar A in the insulatingmaterial. The outer surface of the insulating material beyond the endsof bar A forms an extension of the surface of the portion conformed tothe bar.

The end portions 1) of the insulating material beyond the ends or thebar A may be plugged with insulating material or a disc of insulatingmaterial may be secured within the end portions 1) to prevent leakage ofcurrent to the end of the bar A from a contact carried by the bar.

The method according to this invention, for the production of contactbars of the structure described, will be made apparent by reference toFigures 1-5.

A plurality of approximately square metal bars A, bored and tapped attheir ends, as at an, are assembled together, as shown in Figure 1, bymeans of circular rods 0 provided with reduced threaded ends d,d, forengagement in the tapped ends !a of the bars A.

The circular rods 0 will be of a diameter not in excess of, anddesirably about equal to, the minor dimension of the face of the bar. Ifthe bar A is circular, the rod 0 will be of less diameter than the bar.

A plurality of bars A having been assembled together, the assembly ismounted in any suitable mechanism, for rotation as' a mandrel, andsheets of insulating material B are wound upon the sev eral bars A. i

'I'hesheets of insulating material B,=as has been indicated, may becomposed of any suitable material, as, for example, paper or fabricimpregnated with a synthetic resin, as, for example, a phenolformaldehyde resin.

The sheets of insulating material B, will, as

shown in Figure 1, be of a width greater than the length of the bars A,so that when the sheets are wrapped upon the bars the wrapping will'extend beyond the ends of the bars over a portion of the circular rods0. p

The wrapping having been completed; the Wrapped bars A will appear asshown in Figures 2 and 3, from an inspection of which it will be notedthat the insulating material B will conform to the faces of the barsthroughout their length and will extend beyond the ends of the bars overthe rods 0, being in contact therewith only along lines where thediameter of the rods equals the dimensions of the ends of the bars A.

The wrapped assembly is now placed in a mold conforming to the contourof the bars A and rods c and heat and pressure applied to compress andconform the insulating material B to the bars A and rods and to set theresin.

As shown in Figures 4 and 5, the pressure applied in the mold compressesthe insulating material and conforms it to the faces of the bars A and,at the same time, conforms it to the circular rods 0. The portions ofthe insulating material conformed to the rods 0 are somewhat less densethan that conformed to the faces of the bars. However, such portions ofthe covering which extend beyond the metal bar extend inwardly across aportion of each end of the metal bar forming abutments for each end ofthe metal bar as shown at :1: in Figure 5.

When the molding is completed, the assembly is removed from the mold andfinally the several insulated contact bars are unscrewed from theseveral rods 0, which are then available for the assembly of furtherbars to be wrapped.

In Figures 8-10, I have illustrated one form of circuit breaker providedwith a connector bar such as shown in Figures 6 and '7 and in use with acircuit breaker provided with three contacts one being omitted at theleft end in Figure 10.

Referring to Figure 8, the circuit breaker is mounted on a slab ofinsulation H], which, in turn, is mounted on a suitable support (notshown). The circuit breaker is provided with a supporting frame ofU-shape for the actuating mechanism having a base l2 which is secured tothe slab It, extending from each end of the base i2 is a flange 14 andextending from each flange I4- are arms l6 and [8. The upper ends ofarms 18 are connected to each other by a cross bar 20 while the arms 15are kinked as at 22 so that the upper portions of the arms it are closerto each other than the lower portions or flanges l4 as shown in Figure10 and form stops for a spring carrying yoke 24 for the purposehereinafter described. Extending outwardly from the flange Id at eachside of the supporting frame between the arms i6 and It in the plane ofarms l8 and the fianges M is a projection 26, one being shownin dottedlines in Figure 8. The yoke 24 is provided with an arm 28 at each sidewhich extends toward the projections 26, each being mounted on atrunnion 33 extending inwardly from a projection 25 on which the yoke 24is adapted to move from the position shown in Figure 8 until the arms 28engage the inwardly kinked portions of arms it which are in the sameplane as arms 28 (see Figure 10).

Connected to the arms is is a fixed shaft 32 and rotatably mounted onshaft 32 extending from one arm 18 to the other is a sleeve 34.Connected to the sleeve 34 intermediate its ends is an actuatinglever 36having a handle 38 connected thereto. The outer end of lever 36 isprovided with a keeper 4!] which is engaged by a latch 42 to retain thelever in the position shown in Figure 9 when the switch is closed. Theactuating lever 38 is also provided with a projection 43 which engagesbar 26 to limit the movement of the lever 36 in a counterclockwisedirection.

Each movable contact 44 is adapted to be moved into contact with a fixedcontact 4'6 mounted on the slab II), the movable contact being carriedon one end of a lever 48, the other end of the lever having spacedprojections 5!] which extend through an opening in the web 52 of achannel-shaped rocker arm 53 having flanges 54 extending from the web52. The projections are pivotally mounted on a fixed shaft 56 connectedto the flanges 54.

The flanges 54 of the rocker arm 53 are each provided with a squareopening, through which the connector bar extends and is clamped inposition against theweb 52 by a clamp 58 having projections 60 extendingthrough openings in the web 52 and are riveted over the outer face ofthe web to firmly clamp the rocker arm in position on the connector bar.Extending from the contact carrying end of lever 48 is a fixed screw 62which extends through a slot in the end of an extension 64 of the web 52of the rocker arm 53, the end of the screw being provided with anadjusting nut 66 and a nut lock 88 for adjusting the position of thecontact 44 relative to extension 64, and 19 is a spring surroundingscrew 62 to maintain contact arm 48 spaced from the extension 6.

As previously stated, a circuit breaker such as illustrated herewithcomprises three movable contacts each carried by a rocker arm 53 shiftedby the movement of a connector bar, one of which rocker arms is locatedcentrally of the connector bar within the supporting framefor theactuating mechanism between the arms 28 of the yoke 24 and one as shownat the right of the actuating mechanism as shown in Figure 10, the oneat theleft 'not being shown.

a The central rocker arm 53 for the central movable contact is pivotallymounted on a fixed shaft it? which is fixedly connected to the flangesI4 of the frame of the actuating mechanism and extends through theflanges 54 of the central rocker arm 53, about the axis of which thethree rocker arms, together with the connector bar A, are oscillated toclose and open the circuit breaker as hereinafter described.

Pivotally connected to each side of actuating lever 36 at 14 is a link15 which is pivotally mounted at the other end on a pin 18, the linksbeing spaced from each other by a washer on the pin l8.

Fivotally mounted on the pin 78 at the outside of each link 14 is a link82, the other ends of each link 82 are pivotally connected to shaft 56connected to the flanges 54 of the central rocker arm 53-.

Pivotally mounted on the outer portion of each end of pin '18 is awalking beam 84. Extending from the connecting member of the yoke 24 aretwo projections 86, each being in the plane of a walking beam 84, eachprojection 86 being provided with two openings, while each Walking beamis provided with an opening in each end. Each walking beam 34 isconnected to the projection in the same plane by two tension springs 88whose ends extend through an opening in a walking beam and an opening ina projection 35, the arrangement of the springs resisting the movementof the rocker arms about the axis of shaft '52 in a countercloclw'lisedirection or in the direction to close the circuit breaker and to placethe actuating lever under a predetermined spring load to open thecircuit breaker with a snapping action when the release mechanismwithdraws the latch to permit the springs 88 to break the circuit.

In order to close the circuit breaker, the handle 38 is presseddownwardly to rock actuating lever 26 until the arms 28 of the yokeengage arms In of the supporting frame to the position shown in Figure9, at which time the actuating lever 36, together with the walkingbeams, will be in the positions shown in dotted lines in Figure 9, (thesprings 88 being omitted for clearness), in the further movement of theactuating lever 36, the rocker arms 53 will rotate about the axis ofshaft 72, first closing the contacts and then compressing springs 10 asshown in Figure 9 at which time the actuating lever 36 will be locked bylatch 42 to retain the circuit breaker in its closed position.

The leads from fixed contacts 46 as well as from levers 48 carryingmovable contacts have been omitted for clearness. Connector bars of thischaracter have been open to objection in that no means were provided toinsure against movement between the metal bar and the insulatingcovering.

It is well known that bars of this type have been formed of steel ofsubstantial size covered with insulation as they are subjected toconsiderable torque. When a number of contacts are connected to thecovering of the bar in cases where there is the slightest movementbetween the bar and the insulating covering, a slight time lag is causedbetween the separation of adjacent switch contacts mounted on the sameconnector bar and the contacts with which they cooperate to open orclose a circuit due to the torque to which the covering is subjectedwhen the bar is rocked to open the switches which cause arcing betweencooperating switch contacts due to the lag between adjacent contactcarrying arms.

By the conforming of the insulating covering about the faces of the barthroughout the length thereof and about the end edges of the bar betweenthe periphery of the bar and the rods about which the ends of theinsulation are formed, all danger of starting separation of theinsulating covering from the metal bar is avoided, as well as endwisemovement of the bar in the covering, as the insulating covering is notonly cemented to the entire periphery of the metal bar, but the portionsof the covering extend over the ends of the bar between the periphery ofthe bar and the openings in the extending portions, so that the metalbar is gripped between the portions of the insulating covering extendingover the ends of the metal bar.

This application is a continuation-in-part of my application Serial No.574,121, filed January 23, 1945, now abandoned, which was a division ofmy application Serial No. 538,222, filed June 1, 1944, now Patent No.2,446,490, issued August 1, 1948.

What I claim and desire to protect by Letters Patent is:

1. A rockable connector bar to which electrical switch contact carryingrocking arms are adapted to be clamped in spaced relation together witha connector bar rocking member under a predetermined spring load forsnapping open the switches, comprising a metal bar having a continuousinsulating covering extending beyond each end of the metal bar, saidcovering being molded to the outer face of the metal bar and across aportion of each end of the metal bar to resist movement of theinsulating covering relative to the metal bar caused by torque due tothe snapping action of the spring to which the connector bar issubjected while shifting the rocker arms by the connector bar rockingmember when opening the switches.

2. A rockable connector bar to which electrical switch contact carryingrocking arms are adapted to be clamped in spaced relation together witha connector bar rocking member under a predetermined spring load forsnapping open the switches, comprising a metal bar of rectangularcross-section having a continuous insulating covering extending beyondeach end of the metal bar, said covering being molded to the outer faceof the metal bar and across a portion of each end of the metal bar overat least the corners thereof to resist movement of the insulatingcovering relative to the metal bar caused by torque due to the snappingaction of the spring load to which the connector bar is subjected whileshifting the rocker arms by the connector bar rocking member whenopening the switches.

WAYNE R. SCHERER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,963,856 Lewis et a1 June 19,1934 2,439,084 Graves Apr. 6, 1948

